A collection of coins, medals and watches worth £53,000 has been stolen from a museum's storage facility. The 1,000 artefacts from the Derby Museum and Art Gallery's city-based storage site were stolen some time between 2 May and 19 June, Derbyshire police said. None of the items have been found.

Among the hoard is a collection of about 20 18th- and 19th-century gold and silver watches worth up to £3,000 each. These includes examples made by clockmaker and scientist John Whitehurst, who was a member of the Midlands' based Lunar Society, and a contemporary of famous Derby artist Joseph Wright.

Coins dating back more than 800 years have also been stolen, as well as more modern coins from the early 20th century. The items were locked away and only used for exhibitions and special viewings.

A spokeswoman for Derbyshire police said museum staff had worked on the collection recently, but the thefts came to light only when another museum made a request to borrow some of the items.

The theft was recorded with the Metropolitan police arts crime unit as well as the Arts Council England security advisory service in the hope that the thief would try to sell them.

Meanwhile, additional security measures and procedures have been put in place at the storage facility.

Investigating officer Detective Constable Dee Hornblower said: "There has been no sign of a break-in at the premises, so the possibility that this was carried out with inside knowledge has at this stage not been ruled out. We have circulated details of the stolen items to every police force in the country in the hope that they can be traced."

Derby city council cabinet member for leisure and culture Martin Repton said: "Our ultimate fear is that some of these items which are of a relative low monetary value could potentially be discarded by the culprit or culprits, meaning that they would be lost for ever with little chance of recovery.

"We are therefore also appealing to members of the public who may have any information to contact Derbyshire police."

Anyone with information about the incident, or the whereabouts of the stolen items, should call police on 101 or Crimestoppers anonymously on 0800-555 111.